1. Field of the Invention
The present invention relates to a clip for holding a first and a second part together.
2. Description of the Related Art
These types of mounting clips find numerous applications, in particular in the automotive industry for mounting two pieces of equipment together. In particular, the clip can be used for mounting trim on an element of the vehicle structure. This trim is visible inside the cabin and for esthetic reasons the mounting must be invisible.
A mounting clip of the above mentioned type is described in document EP1482184 in which the mounting clip comprises a summit base from which a pair of external lateral legs is extending and between which is placed a pair of internal lateral legs, also connected to the summit base. The flexible external legs comprise elements that snap in the opening of the first piece. Each internal leg, adjacent to an associated external leg, comprises a first portion connected to the summit base and is extended by a second portion which is bent backward towards the inside of the clip in direction of the summit base. Each second portion is composed of an inside directed folding zone and a blade with free lateral displacement. The blades of the two internal legs, directly opposite of each other, delimit between them a central space for axial insertion of a tang carried by the second piece. Each blade with free lateral displacement carries a catch element for the tang, pointing in direction of the central space in order to retain the tang inside the central space. The catch elements are projecting continually inside the central space, regardless of the status of the clip, in other words whether or not the clip is snapped in the first piece and whether or not the tang of the second piece is inserted in the central space.
Because of this projecting arrangement of the catch elements, the axial insertion of the tang of the second piece results in external deterioration of the tang, in the form of permanent superficial deformations such as cuts or scores, which are axially generated by the catch elements. The deterioration of the tang results in a less reliable mounting of the second piece, which becomes susceptible of vibrating and therefore a source of noise, even resulting in fortuitous detachment of the second piece. In addition, the force for installing the clip on the tang is high taking into account the interaction between the catch elements and the tang.
On the other hand, starting from the normal situation where the second piece is attached to the first piece by means of the clip in snapped position, any axial displacement of the tang (resulting from an axial force applied on the tang) provokes a corresponding axial withdrawal of the clip (thanks to the engagement of the catch elements in the tang) relative to the opening of the first piece. This axial movement of the clip is accompanied by a progressive withdrawal of the catch elements, involving reduced retention relative to the second piece. Therefore, the fastening of the clip to the second piece decreases progressively as soon as the clip starts to withdraw axially, notwithstanding that the clip is still snapped in the first piece. In other words, from the beginning of the axial withdrawal of the clip, the retention quality of the second piece by the clip decreases in inverse proportion to the value of the axial displacement of the clip, with as consequence reduced reliability of the mounting of the second piece, which is susceptible of vibrating and of becoming a source of noise. In case of voluntary disassembly of the mounting between pieces, sliding is even likely to occur between the clip and the mounting tang of the second piece.